(a) Field of the Invention
The present invention relates to a thin film transistor array panel and a manufacturing method thereof.
(b) Description of the Related Art
Among display panels, liquid crystal displays (LCD) are a type of flat panel display that is currently being widely used. LCDs include two display panels on which field generating electrodes such as a pixel electrode and a common electrode, etc., are formed, and a liquid crystal (LC) layer disposed therebetween. To display an image on an LCD display a voltage is applied to the field-generating electrodes to generate an electric field across the LC layer. The voltage applied to the LC layer determines the orientation of LC molecules therein to adjust polarization of incident light. In the liquid crystal display, the pixel electrode and the common electrode that generate the electric field across the liquid crystal layer may be formed on a thin film transistor array panel.
In one aspect of a liquid crystal display, a pad portion connects a driving circuit on the thin film transistor array panel. The driving circuit is used apply a gate voltage and a data voltage to the field generating electrode of the liquid crystal display. In a case in which the thickness of a passivation layer on the thin film transistor array panel is excessive, the height of a contact hole that exposes the pad portion is increased. As a result, a connecting member connecting the driving circuit and pad portion may easily become disconnected. Furthermore, in the case of the gate pad portion, a gate insulating layer is also disposed on the gate pad portion, and thus the height of the contact hole that exposes the gate pad portion is further increased.
In particular, when forming two field generating electrodes in the thin film transistor array panel, and when using an organic insulator as a passivation layer, the height of the contact hole that exposes the pad portion is further increased.
When manufacturing a liquid crystal display, a photolithography process is used for patterning a thin film layer of the thin film transistor; however the manufacturing cost is increased as the number of photomasks for the photolithography process is increased.
The above information disclosed in this Background section is only for enhancement of understanding of the background and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.